The present invention relates to a chamber at least for the transport of workpieces, particularly of circular-disk-shaped workpieces, such as storage disks, at least at times, into the vacuum atmosphere, during their manufacturing, comprising at least two exterior openings for the guiding-through of a workpiece and comprising a majority of workpiece receiving devices which can be rotated jointly about an axis inn an assignment to the openings, to a chamber combination, to a vacuum treatment facility, and to a transport method.
For the transport of workpieces, particularly of storage disks, such as CD's, magnetic or magneto-optic storage disks, in a chamber of a vacuum treatment facility, for example, for the treatment of the workpieces by reactive or non-reactive vacuum processes, such as etching processes, physical or chemical coating processes with or without glow discharge support, U.S. Pat. No. 3,856,654 and DE 24 54 544 describe a plurality of workpiece receiving devices which can be rotated jointly about an axis in an alignment with provided exterior openings of the chamber.
In particular, U.S. Pat. No. 3,856,654 shows frame-type workpiece receiving devices which rotate in the chamber about an axis in the manner of a carrousel. When a frame containing the workpiece has reached the alignment position with the exterior opening of the chamber on which a working station is mounted, the workpiece is pushed into the treatment position by a lifting element which operates parallel to the rotation axis. This resulted in a three-dimensional displacement path for the workpieces, specifically in two dimensions according to the plane of rotation of the carrousel and in a third dimension, parallel to the rotation axis of the carrousel out of the chamber.
DE-PS 24 54 544 suggests a configuration in which the displacement path in the third dimension is reduced considerably in order to achieve a more compact construction. For this purpose, the workpieces are displaced in the treatment position only slightly parallel to the axis within the suspension framework by which workpiece receiving frames are disposed on the rotating carrousel so that they can be displaced axially. For this purpose, a ram is mounted to be aligned with the respective exterior opening with the treatment station and engages on the workpiece holding frame opposite the treatment chamber. Thus, the wall of the treatment station mounted to the exterior opening of the chamber is completed by a part rotating with the carrousel.
In the facilities described in DE-OS 39 12 295, 40 09 603, 37 16 498 and in EP-A 0 389 820, this principle is also pursued in partially constructive variants.
In the known manufacturing processes, particularly of the above-mentioned circular-disk-shaped workpieces, however, it becomes increasingly necessary to carry out a plurality of individual treatment steps on a corresponding number of treatment stations. The approach in which the workpieces in the treatment position were lifted only minimally on the transport plane of the workpiece holding carrousel is only a limited remedy in this case because the available space on the chamber with the carrousel is limited.
It is one object of the present invention to solve this problem based on a chamber with a carrousel-type conveyer by providing that at least one transport element is provided which is aligned with an opening, is disposed in the chamber independently of the rotatable workpiece receiving devices, can be moved out and back in a radially controlled manner in at least one component, and engages on a workpiece in the opening area.
In addition, a transport element is provided which can be moved out and back at least in one motion component radially to the rotation axis of the workpiece receiving devices in a controlled manner and which is disposed in the chamber independently of the carrousel. As a result, it becomes possible to particularly radially move the workpiece back and forth at given rotating positions, specifically when a receiving device on the carrousel is aligned with one of the exterior openings of the chamber to be serviced, with a stroke that can be selected according to the circumstances. Consequently, starting from the carrousel, the workpieces can be conveyed through the exterior openings and nevertheless, in the event of an only radial movement, the two-dimensionality of the transport path is fully maintained. In the event of a movement of the transport element that is only partially radial, if desired, the extent of the transport movement in the third dimension can be selected arbitrarily. Because the carrousel diameter is determined by the size and mainly by the number of its workpiece receiving devices, and the axial dimension of the chamber does not affect this number, the linear stroke of the transport element is placed in a plane of the chamber which is large as a result of the number in accordance with the present invention. Thus, without any enlargement of the chamber, space is available for a long transport stroke.
With respect to yet another object of the invention is to overcome the recognized additional disadvantage of the previously known carrousel transport techniques, namely the need for additional elements on the chamber in order to, even though partially to a minor extent, transport the workpieces from the carrousel transport plane in the direction of the respective treatment stations. The need for such additional elements particularly stands in the way of a flexible facilities capable of different configurations that are adapted to specific requirements because of the fact that the interaction of the carrousel and the additional elements is aimed at the respective chamber configuration with its specifically provided exterior openings.
If, for example, in such a configuration of the facility, one of the provided exterior openings is not lined up with a treatment station but is closed by a cover, the additional transport element must nevertheless be provided and assigned to this opening in order to be able to use the same chamber in a different configuration of the facility.
A further object of the present invention is to provide an improved chamber in which the mutual physical arrangement of the exterior openings with respect to a rotation axis about which, in this case, at least one workpiece receiving device rotates, can be selected arbitrarily within wide limits and/or which provides the possibility of being able to construct overall extremely compact facilities having high efficiency.
This object achieved in the German Patent Application P 41 17 969.2 with parallel applications in Europe No. 92 108 771.4, in above-referenced U.S. Pat. No. 5,245,736, in Japan No. 4-140 357. A chamber is described there in which the workpiece receiving devices are arranged on a transport element which, as a whole, is disposed to be driven about the axis in a rotationally movable manner and which, in addition, can be linearly moved and moved back with respect to this axis. The compactness of treatment facilities of this type are significantly improved if, according to the second aspect of the present invention, an approach is followed which also significantly increases the constructive degree of freedom.
In one currently preferred chamber combination according to the invention, a chamber is provided as an additional chamber, that is, a chamber comprising the workpiece receiving carrousel and a radially operable transport element which is disposed independently of it.
In the carrousel chamber, whether separately or in the above-mentioned combination, the transport element which is disposed independently with respect to the plurality of rotatable workpiece receiving devices can be non-rotatably disposed in the chamber. It is also within the scope of the present invention, however, to arrange this transport element rotatably with respect to the axis of the carrousel but independently of the latter. Thus, for example, by way of such a transport element, several exterior openings may be serviced, whereas, in another currently preferred embodiment, one transport element, which is disposed in a non-rotatable manner, must be assigned to each exterior opening to be serviced thereby.
In the case of a chamber with the carrousel or in the case of a chamber combination with this chamber on the latter, or in a chamber combination with a chamber in which the transport element is constructed to be rotationally movable and linearly displaceable, it is achieved according to one aspect of the present invention that a workpiece which travels through this chamber toward a treatment and then travels back through this chamber from the treatment, remains much longer in the chamber on the way there than on the way back. As a result, a conditioning of the workpieces in this chamber is possible before their treatment, such as a degasification, for the purpose of which the mentioned chamber may definitely be heated or another pretreatment process may be used.
Mainly the chamber with the carrousel is preferred for this purpose because a significantly larger number of workpiece receiving devices may be provided on the carrousel than on the chamber on which the transport element is disposed in a rotationally movable as well as linearly movable manner, specifically with much lower expenditures, if it is considered that the enlargement of the carrousel is only a question of the chamber dimension, whereas the multiplication of the rotationally and linearly movable transport elements results in a significant increase of the complexity of the chamber.
On the chamber with the carrousel as well as on the chamber with the rotationally and linearly moved transport element and thus also on the chamber combination, it is currently preferred in accordance with another aspect of the present invention to configure at least one transport element so that it can be moved out and back at a right angle with respect to the pertaining rotational axis. Consequently, this configuration maintains the two-dimensionality of the transport path, whether this is in addition to the two-dimensional transport path with the carrousel or in addition to the rotating movement and thus to the two-dimensional movement of the transport element.
Although it is easily possible to arrange on all chambers or chamber combinations described here disk-shaped workpieces with their disk faces in the respective rotating planes, and thus to arrange the workpiece receiving devices correspondingly, it is preferred according to the present invention to arrange for such disk-shaped workpieces the workpiece receiving device such that its receiving surface during the rotation, whether of the carrousel or of the transport element, sweeps over a cylindrical surface.
The chamber with the carrousel or a chamber combination with this carrousel chamber is also constructed such that the several workpiece receiving devices have a drive that affects their axis of rotation, or that the drive in this respect affects the workpiece receiving devices peripherally.
As a result, it is achieved in a constructively simple manner that the carrousel drive and the drive of the additional transport element, whether this is a rotational and radial drive or only a radial drive, can be separated in the chamber in a space-saving manner.
The above-mentioned chamber with the carrousel, also in the above-mentioned combination, can also be constructed so that the several workpiece receiving devices are disposed in a radially springy manner and, by the at least one transport element, which is disposed independently of the rotatable workpiece receiving device, can be placed against the border to the opening, sealing elements preferably being provided in this case for a tight, preferably vacuum-tight, closing-off of this opening.
As a result of the fact that the receiving devices are disposed in a radially springy manner, they can, if they are aligned to an exterior opening to be serviced, be placed against the opening border by the transport element until a vacuum-tight closure is achieved, whereby, viewed from the interior of the chamber, the workpiece receiving device on the mentioned opening is situated outside the chamber while the opening closure is tight. The mentioned workpiece receiving device can therefore be serviced from the outside of the chamber by the inserting or removing of a workpiece without any undesirable impairment of the atmosphere in the respective chamber.
Furthermore, controlled holding elements are provided particularly on the workpiece receiving devices of the chamber with the carrousel, in which controlled holding elements for a workpiece are provided and these can be actuated at predetermined rotating positions, preferably when the workpiece receiving device is positioned in an opening area, by means of a mechanical engagement. It should be explicitly mentioned, however, that such holding elements may also be provided on the workpiece receiving device on the transport element which can be provided in a rotationally movable as well as in a linearly movable manner.
In a further currently preferred variant according to the present invention, that at least some of the exterior openings on the chamber with the carrousel or on the chamber with the linearly and radially movable transport element of the combination are tightly, preferably vacuum-tightly, closable by the effect of the at least one transport element. In the chamber with the carrousel, this is implemented by the at least one transport element which can be radially moved out and back whereas in the chamber combination, it is implemented by the rotationally movable and linearly displaceable transport element.
If, in the case of the above-mentioned combination, a chamber with a carrousel and one with a linearly and rotationally movable transport element are combined, a respective common exterior opening of the chambers is closed off tightly, preferably vacuum-tightly, preferably by the transport element of one chamber as well as by that of the other chamber.
Depending on the requirement of the atmospheric uncoupling of the two chambers, a sealing may be sufficient by means of a gap or diaphragm gland sealing in the sense of a pressure stage, or both chambers are separated in a vacuum-tight manner.
A vacuum treatment facility comprising a chamber with a carrousel or with the above-mentioned chamber combination is achieved in that the chamber has at least three exterior openings, of which at least one communicates with an intermediate storage chamber, and a two-way transport element is provided in order to transport at least one workpiece respectively from the chamber into the intermediate storage chamber and vice versa.
The transport method according to the present invention is achieved in that a rotating transport element is provided in the intermediate storage chamber, by means of which in each case the at least one fed workpiece is moved through the intermediate storage chamber for the purpose of its return transport into the chamber within preferred embodiments, the intermediate storage chamber constructed preferably as a degasification chamber for the workpieces.